jcsp.awt
Class ActiveWindow

java.lang.Object
  |
  +--java.awt.Component
        |
        +--java.awt.Container
              |
              +--java.awt.Window
                    |
                    +--jcsp.awt.ActiveWindow

All Implemented Interfaces:

Accessible, CSProcess, ImageObserver, MenuContainer, Serializable

public class ActiveWindow

extends Window

implements CSProcess

java.awt.Window with a channel interface.

Process Diagram

                              __________________
                             |                  |
                             |                  | event 
                             |                  |----->-----
                             |                  | (java.awt.event.WindowEvent)
                             |                  |
                             |                  | containerEvent
                             |                  |----->-----
                             |                  | (java.awt.event.ContainerEvent)
                             |                  |
                             |                  | componentEvent
                             |                  |----->-----
                             |                  | (java.awt.event.ComponentEvent)
                             |                  |
                   configure |                  | focusEvent
                  ----->-----|   ActiveWindow   |----->-----
 (ActiveComponent.Configure) |                  | (java.awt.event.FocusEvent)
                             |                  |
                             |                  | keyEvent
                             |                  |----->-----
                             |                  | (java.awt.event.KeyEvent)
                             |                  |
                             |                  | mouseEvent
                             |                  |----->-----
                             |                  | (java.awt.event.MouseEvent)
                             |                  |
                             |                  | mouseMotionEvent
                             |                  |----->-----
                             |                  | (java.awt.event.MouseEvent)
                             |__________________|  
 

Description

ActiveWindow is a process extension of java.awt.Window with channels for run-time configuration and event notification. The event channels should be connected to one or more application-specific server processes (instead of registering a passive object as a Listener to this component).

All channels are optional. The configure and event channels are settable from a constructor. The event channel delivers a WindowEvent whenever one is generated on the ActiveWindow. Other event channels can be added to notify the occurrence of any other events the component generates (by calling the appropriate addXXXEventChannel method before the process is run). Messages can be sent down the configure channel at any time to configure the component. See the table below for details.

All channels are managed by independent internal handler processes. It is, therefore, safe for a serial application process both to service an event channel and configure the component -- no deadlock can occur.

IMPORTANT: it is essential that event channels from this process are always serviced -- otherwise the Java Event Thread will be blocked and the GUI will stop responding. A simple way to guarantee this is to use channels configured with overwriting buffers. For example:

   final One2OneChannel myMouseEvent =
     One2OneChannel.create (new OverWriteOldestBuffer (n));
 
   final ActiveWindow myWindow = new ActiveWindow ();
   myWindow.addMouseEventChannel (myMouseEvent);
 

This will ensure that the Java Event Thread will never be blocked. Slow or inattentive readers may miss rapidly generated events, but the n most recent events will always be available.

Channel Protocols

Input Channels
configure	Boolean	If this is the Boolean.TRUE object, the window is made visible If this is the Boolean.FALSE object, the window is made invisible Other Boolean objects are ignored
	ActiveWindow.Configure	Invoke the user-defined Configure.configure method on the window.
Output Channels
event	WindowEvent	The WindowEvent generated by the component
containerEvent	ContainerEvent	See the addContainerEventChannel method.
componentEvent	ComponentEvent	See the addComponentEventChannel method.
focusEvent	FocusEvent	See the addFocusEventChannel method.
keyEvent	KeyEvent	See the addKeyEventChannel method.
mouseEvent	MouseEvent	See the addMouseEventChannel method.
mouseMotionEvent	MouseEvent	See the addMouseMotionEventChannel method.

Example

 import java.awt.*;
 import java.awt.event.*;
 import jcsp.lang.*;
 import jcsp.util.*;
 import jcsp.awt.*;
 
 public class ActiveWindowExample {
 
   public static void main (String argv[]) {
 
     final Frame root = new Frame ("ActiveWindow Example");
 
     final One2OneChannel event =
       One2OneChannel.create (new OverWriteOldestBuffer (10));
 
     final ActiveWindow window = new ActiveWindow (null, event, root);
 
     root.setSize (400, 400);
     root.setVisible (true);
     window.setVisible (true);
 
     new Parallel (
       new CSProcess[] {
         window,
         new CSProcess () {
           public void run () {
             while (true) {
               WindowEvent w = (WindowEvent) event.read ();
               System.out.println (w);
             }
           }
         }
       }
     ).run ();
   }
 
 }
 

Author:

P.D.Austin and P.H.Welch

See Also:

Window, ContainerEvent, ComponentEvent, FocusEvent, KeyEvent, MouseEvent, OverWriteOldestBuffer, Serialized Form

Inner Class Summary

static interface

ActiveWindow.Configure This enables general configuration of this component.

Inner classes inherited from class java.awt.Window

Window.AccessibleAWTWindow

Inner classes inherited from class java.awt.Container

Container.AccessibleAWTContainer

Inner classes inherited from class java.awt.Component

Component.AccessibleAWTComponent

Fields inherited from class java.awt.Component

BOTTOM_ALIGNMENT, CENTER_ALIGNMENT, LEFT_ALIGNMENT, RIGHT_ALIGNMENT, TOP_ALIGNMENT

Fields inherited from interface java.awt.image.ImageObserver

ABORT, ALLBITS, ERROR, FRAMEBITS, HEIGHT, PROPERTIES, SOMEBITS, WIDTH

Constructor Summary

ActiveWindow(ChannelInput configure, ChannelOutput event, Frame f)
Constructs a new ActiveWindow.

ActiveWindow(Frame f)
Constructs a new ActiveWindow.

Method Summary

void	addComponentEventChannel(ChannelOutput componentEvent) Add a new channel to this component that will be used to notify that a ComponentEvent has occurred.
void	addContainerEventChannel(ChannelOutput containerEvent) Add a new channel to this component that will be used to notify that a ContainerEvent has occurred.
void	addFocusEventChannel(ChannelOutput focusEvent) Add a new channel to this component that will be used to notify that a FocusEvent has occurred.
void	addKeyEventChannel(ChannelOutput keyEvent) Add a new channel to this component that will be used to notify that a KeyEvent has occurred.
void	addMouseEventChannel(ChannelOutput mouseEvent) Add a new channel to this component that will be used to notify that a MouseEvent has occurred.
void	addMouseMotionEventChannel(ChannelOutput mouseMotionEvent) Add a new channel to this component that will be used to notify that a MouseMotionEvent has occurred.
void	run() The main body of this process.
void	setConfigureChannel(ChannelInput configure) Sets the configuration channel for this ActiveWindow.

Methods inherited from class java.awt.Window

addNotify, addWindowListener, applyResourceBundle, applyResourceBundle, dispose, finalize, getAccessibleContext, getFocusOwner, getGraphicsConfiguration, getInputContext, getListeners, getLocale, getOwnedWindows, getOwner, getToolkit, getWarningString, hide, isShowing, pack, postEvent, processEvent, processWindowEvent, removeWindowListener, setCursor, show, toBack, toFront

Methods inherited from class java.awt.Container

add, add, add, add, add, addContainerListener, addImpl, countComponents, deliverEvent, doLayout, findComponentAt, findComponentAt, getAlignmentX, getAlignmentY, getComponent, getComponentAt, getComponentAt, getComponentCount, getComponents, getInsets, getLayout, getMaximumSize, getMinimumSize, getPreferredSize, insets, invalidate, isAncestorOf, layout, list, list, locate, minimumSize, paint, paintComponents, paramString, preferredSize, print, printComponents, processContainerEvent, remove, remove, removeAll, removeContainerListener, removeNotify, setFont, setLayout, update, validate, validateTree

Methods inherited from class java.awt.Component

action, add, addComponentListener, addFocusListener, addHierarchyBoundsListener, addHierarchyListener, addInputMethodListener, addKeyListener, addMouseListener, addMouseMotionListener, addPropertyChangeListener, addPropertyChangeListener, bounds, checkImage, checkImage, coalesceEvents, contains, contains, createImage, createImage, disable, disableEvents, dispatchEvent, enable, enable, enableEvents, enableInputMethods, firePropertyChange, getBackground, getBounds, getBounds, getColorModel, getComponentOrientation, getCursor, getDropTarget, getFont, getFontMetrics, getForeground, getGraphics, getHeight, getInputMethodRequests, getLocation, getLocation, getLocationOnScreen, getName, getParent, getPeer, getSize, getSize, getTreeLock, getWidth, getX, getY, gotFocus, handleEvent, hasFocus, imageUpdate, inside, isDisplayable, isDoubleBuffered, isEnabled, isFocusTraversable, isLightweight, isOpaque, isValid, isVisible, keyDown, keyUp, list, list, list, location, lostFocus, mouseDown, mouseDrag, mouseEnter, mouseExit, mouseMove, mouseUp, move, nextFocus, paintAll, prepareImage, prepareImage, printAll, processComponentEvent, processFocusEvent, processHierarchyBoundsEvent, processHierarchyEvent, processInputMethodEvent, processKeyEvent, processMouseEvent, processMouseMotionEvent, remove, removeComponentListener, removeFocusListener, removeHierarchyBoundsListener, removeHierarchyListener, removeInputMethodListener, removeKeyListener, removeMouseListener, removeMouseMotionListener, removePropertyChangeListener, removePropertyChangeListener, repaint, repaint, repaint, repaint, requestFocus, reshape, resize, resize, setBackground, setBounds, setBounds, setComponentOrientation, setDropTarget, setEnabled, setForeground, setLocale, setLocation, setLocation, setName, setSize, setSize, setVisible, show, size, toString, transferFocus

Methods inherited from class java.lang.Object

clone, equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

ActiveWindow

public ActiveWindow(Frame f)

Constructs a new ActiveWindow.

Parameters:

f - the parent frame for the window.

ActiveWindow

public ActiveWindow(ChannelInput configure,
                    ChannelOutput event,
                    Frame f)

Constructs a new ActiveWindow.

Parameters:

configure - the channel for configuration events -- can be null if no configuration is required.

event - the WindowEvent will be output whenever it occurs -- can be null if no notification is required.

f - the parent frame for the window.

Method Detail

setConfigureChannel

public void setConfigureChannel(ChannelInput configure)

Sets the configuration channel for this ActiveWindow. This method overwrites any configuration channel set in the constructor.

Parameters:

configure - the channel for configuration events. If the channel passed is null, no action will be taken.

addContainerEventChannel

public void addContainerEventChannel(ChannelOutput containerEvent)

Add a new channel to this component that will be used to notify that a ContainerEvent has occurred. This should be used instead of registering a ContainerListener with the component. It is possible to add more than one Channel by calling this method multiple times If the channel passed is null, no action will be taken.

NOTE: This method must be called before this process is run.

Parameters:

containerEvent - the channel down which to send ContainerEvents.

addComponentEventChannel

public void addComponentEventChannel(ChannelOutput componentEvent)

Add a new channel to this component that will be used to notify that a ComponentEvent has occurred. This should be used instead of registering a ComponentListener with the component. It is possible to add more than one Channel by calling this method multiple times If the channel passed is null, no action will be taken.

NOTE: This method must be called before this process is run.

Parameters:

componentEvent - the channel down which to send ComponentEvents.

addFocusEventChannel

public void addFocusEventChannel(ChannelOutput focusEvent)

Add a new channel to this component that will be used to notify that a FocusEvent has occurred. This should be used instead of registering a FocusListener with the component. It is possible to add more than one Channel by calling this method multiple times If the channel passed is null, no action will be taken.

NOTE: This method must be called before this process is run.

Parameters:

focusEvent - the channel down which to send FocusEvents.

addKeyEventChannel

public void addKeyEventChannel(ChannelOutput keyEvent)

Add a new channel to this component that will be used to notify that a KeyEvent has occurred. This should be used instead of registering a KeyListener with the component. It is possible to add more than one Channel by calling this method multiple times If the channel passed is null, no action will be taken.

NOTE: This method must be called before this process is run.

Parameters:

keyEvent - the channel down which to send KeyEvents.

addMouseEventChannel

public void addMouseEventChannel(ChannelOutput mouseEvent)

Add a new channel to this component that will be used to notify that a MouseEvent has occurred. This should be used instead of registering a MouseListener with the component. It is possible to add more than one Channel by calling this method multiple times If the channel passed is null, no action will be taken.

NOTE: This method must be called before this process is run.

Parameters:

mouseEvent - the channel down which to send MouseEvents.

addMouseMotionEventChannel

public void addMouseMotionEventChannel(ChannelOutput mouseMotionEvent)

Add a new channel to this component that will be used to notify that a MouseMotionEvent has occurred. This should be used instead of registering a MouseMotionListener with the component. It is possible to add more than one Channel by calling this method multiple times If the channel passed is null, no action will be taken.

NOTE: This method must be called before this process is run.

Parameters:

mouseMotionEvent - the channel down which to send MouseMotionEvents.

run

public void run()

The main body of this process.

Specified by:

run in interface CSProcess